Install new master cylinder without bleeding?

I have done it too many times to count. bench bleed master. The new method is to use plugs supplied with master.
crack lines on old master before anything else. Then remove nuts, then lines. Carefully swap the master cylinder,trying not to bump the lines too much. Snug it all up. The air, if any is at the very highest point, a couple slow gentle brake applications will displace air in lines,and when you release pedal fluid will push air upwards into master cyl.